Fix around 25 tests (under them all tcalval* tests!) by indeed using the save/restore registers code I adjusted earlier.

m68k/cgcpu.pas, tcg68k:
  - remove g_save_registers and g_restore_registers which DID NOT CALL inherited!
  - also remove commented methods g_save_all_registers & g_restore_all_registers


git-svn-id: http://svn.freepascal.org/svn/fpc/trunk@25715 3ad0048d-3df7-0310-abae-a5850022a9f2